Aliens? Aurora? Scientists aren't sure yet

What is that brilliant line in the sky? Is it the trail of an airplane? A message from aliens? Part of the northern lights? Nah, it’s just our buddy Steve. The heavenly phenomenon, given a cutesy name by the Alberta citizen scientists who helped discover him, is still rather mysterious. Our newest (upstairs) neighbour was apparently hiding in plain sight this whole time. Here’s what we know about him so far.

WHO IS STEVE?

Scientists aren’t exactly sure yet what Steve is (a research paper is forthcoming), but he’s not new, and appears closely related to the aurora borealis, or northern lights, which he often appears alongside.

The northern lights (and southern lights, aurora australis) are collisions between charged particles from the sun and gas particles from the Earth’s outer atmosphere.

The colour depends on the gas (yellow-green from oxygen, purple, blue or red from nitrogen).

The high-energy reactions taking place on the surface of the sun throw off huge numbers of charged particles (protons and electrons).

These particles flow toward the Earth in the form of solar wind. Most are deflected by our planet’s magnetic field. But around the poles, the magnetic field is weaker, allowing more particles in.

When a sun particle crashes into a gas atom high above the Earth, it causes the atom to release a photon, a particle of light. Hence the gorgeous display we see in the sky.

FAST FACTS

Thanks to swarm, a group of satellites run by the European Space Agency, we know a few things about Steve.

Steve is:

A band of electrically charged gas particles more than 300 kilometres above the Earth’s surface.

25 km wide and thousands of kilometres long.

Moving at about 6 kilometres per second from east to west across Canada